Locking device for scaffolding elements

ABSTRACT

The invention relates to scaffolding, especially facade scaffolding, comprising vertical poles ( 11 ) located one behind the other, preferably in pairs, and interconnected at given vertical intervals by means of cross struts ( 12 ). Said vertical poles ( 11 ) consist preferably of individual elements ( 11′ ) and form support frames ( 43 ) with said cross struts ( 12 ). Base plates ( 13 ) are also positioned between the cross struts ( 12 ) of neighbouring support frames ( 43 ). Diagonal poles ( 27 ) are arranged between at least some of the neighbouring vertical poles ( 11 ). According to the invention, scaffolding of this type is configured in such a way that at least one end of the diagonal poles ( 27 ) engages in an aperture ( 16 ) provided in the designated vertical pole ( 11 ) by means of a hook ( 15, 15′ ). Said opening lies at least essentially in the plane defined by the axes ( 17 ) of the neighbouring vertical poles ( 11 ).

TECHNICAL FIELD

The present invention relates to a locking device for scaffold platformswhich are provided with a number of hook elements which protrude from atleast two of the sides of the platform in order to, when mounted, behooked up on lying scaffold elements in a scaffold, wherein the lockingdevice is adjustable between a release position, in which the platformscan be unhooked from accompanying scaffold elements, and a lockposition, in which the platform is locked to the scaffold element.

BACKGROUND OF THE INVENTION

Due to the fact that they disclose a high degree of security and auniform strength, scaffold platforms are nowadays used in order toreplace planks. Scaffold platforms are used in order to upholdindividuals and other load in scaffolds, but can be used in a number ofsituations where temporary, movable scaffolds or stands are used, forexample for stage constructions for artist appearances, bridges,landing-stages etc. The platforms can be provided with locking devicesfor locking accompanying hook elements to lying scaffold elements. Thehook elements are open downwards, for which reason the locking devices,and in particular their active part, are arranged so that theyessentially are visible from the under side of the platforms. Onassembly, the hook elements are first hooked on to the lying scaffoldelements so that the platforms rest on these. Next, a separate measureis required in order to adjust the locking device from a releaseposition to lock position. Since the platform is supported in thescaffold in release position as well, there is a risk that the lockingmeasure is not carried out, something which in previously known lockingdevices is unable to be observed when the platform is used, i.e. whenindividuals are situated on the platform. During unfavourable conditionsof loading, the platform may be removed out of its position and beunhooked from the lying scaffold elements. The fact is, that lockposition not only means that the platform is kept in its place, but itcontributes also to a high degree to the overall strength and stabilityof the scaffold.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a locking device, bymeans of which the above-mentioned disadvantages are eliminated.

Said object is achieved by means of the locking device according to theinvention, which is characterized in that the locking device isconstituted by at least one displaceable locking slide which is movablein a guide device between, on the one hand, the release position, inwhich the accompanying scaffold element can be inserted into and takenout of, respectively, the hook elements and, on the other hand, the lockposition, in which the slide blocks the scaffold element in the hookelements, combined with that the locking slide is provided with anindication section, which follows the locking slide's adjustmentmovement between release position and lock position and is adapted to,in release position, protrude clearly visible for an observer from theupper side of the platform for ocular indication that the platform isunlocked, wherein the locking slide is curved and movable in the guidedevice along a curved path.

By means of the locking device according to the invention, a clear,visible indication of the lock status of the locking device is obtained,which indication is obtained from the upper side of the platform aswell, i.e. where users are situated.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be further described in the following with referenceto a preferred embodiment and to the appended drawings, in which

FIGS. 1 and 2 show partly broken side views of a scaffold platform witha locking device according to the invention in release position and lockposition, respectively,

FIGS. 3 and 4 show end views of the scaffold platform with the lockingdevice in release position and lock position, respectively,

FIGS. 5 and 6 show cross sections along the line A—A in FIG. 3 and FIG.4, respectively, and

FIGS. 7 and 8 show partly broken top end elevations of the scaffoldplatform with the locking device in release position and lock position,respectively.

PREFERRED EMBODIMENT

As is apparent from FIGS. 1-8, the locking device 1 according to theinvention is installed on a scaffold platform 2, which is of a type thatdiscloses a number of hook elements 3 that are installed at the ends ofthe platform, wherein only one of the ends is shown in the drawings. Acomplete platform is generally elongated and commonly discloses two hookelements at each end thereof. One single elongated hook element of aprofile may possibly extend over a large part of the width of theplatform, alternatively may several hook elements possibly be arranged,depending on the width of the platform. It is for that matter possiblethat the hook elements instead or also are arranged along the long sidesin a special arrangement in order to provide a high degree ofload-bearing capacity. The scaffold platform 2 is intended to form partof or to be upheld by a scaffold, of which a lying scaffold element 4 isshown in the drawings. In practice, at least two lying, essentiallyhorizontal, scaffold elements are arranged in parallel with each otherwith a relative distance that is adapted to the relative distance of thehook elements in each platform. The scaffold elements 4 are suitablyformed by metal pipes, which in the shown example have a circularcross-sectional form, i.e. a uniform transverse dimension with asymmetry axis which also forms a center of curvature. Generally, thescaffold also includes posts or standing elements which stand on aground and in turn uphold the lying elements 4. A scaffold may consistof a large number of lying elements 4 which are situated on differentlevels and/or the same level in order to uphold a large number ofplatforms in a scaffold. In the shown example, the platform is made upof two parallel longitudinal profile beams 5, between which longitudinalprofile beams transversal profile beams 6 extend at each end. Additionalprofile beams may also be arranged between the longitudinal profilebeams 5. The longitudinal profile beams support a platform plane 7,which forms the upper side of the platform. Advantageously, the entireconstruction is made in light metal, which results in a substantialstrength in relation to the weight. The rest of the scaffold elements,such as the lying scaffold elements 4, are usually pipe constructions,which in the shown example disclose a circular cross-sectional form, butmay alternatively be square profiles or have another form of profile.These elements may be made either in steel or light metal.

Advantageously, the hook elements 3 are also constructed out of a hookedprofile and disclose a hooked section 8 with a free hook end 9, which inthe shown example points downwards in an assembled state, and an insiderest surface 10 which advantageously is adapted to the form and thedimension of the mantle surface 11 of the scaffold element 4, i.e.essentially its arched form. The rest surface 10 discloses an extensionwhich in the shown example essentially corresponds to half the peripheryof the mantle surface 11, which results in that a hook opening 12 isdefined which allows the scaffold element to be inserted into and takenout of, respectively, the hook element. Furthermore, the hook element isprovided with an attachment bracket 13, by means of which the hookelement is fixed to the platform, in this case the profile beam 6.

The locking device 1 according to the invention is best apparent fromFIGS. 3-6. The locking device consists of a locking slide 14 or latch,which is movably installed in a guide device 15 for adjustment between arelease position for the scaffold element 4 and a lock position, inwhich the scaffold element is blocked so that the hook elements will notbe unhooked. The locking slide 14 discloses a curved or bent, archedform, and has an extension which covers at least 90° of a circular arc.Thus, in the shown example, the locking slide is arc-shapely curved inorder to connect to the form of the mantle surface 11 of the lyingscaffold element 4. Therewith, the locking slide discloses a concavelycurved arc-shaped lock surface 16 and a convexly curved guide surface17. Advantageously, as is apparent from the drawings, the center ofcurvature for the locking slide 14 is not entirely coincident with thecenter of curvature 18 for the lying element, by means of which alocking with freedom from play can be assured between locking slide andscaffold element 4 in lock position, see FIG. 6, i.e. so that the locksurface 16 in the locking direction, i.e. downwards in FIG. 6,approaches the scaffold element 4 and in lock position advantageouslypartly bears against the mantle surface 11.

The guide device 15 is adapted to, on the one hand, hold the slide 14fixed to the platform and, on the other hand, guide its adjustmentmovements between lock position and release position, and also assurethat the locking slide in a secure manner is kept in lock position. Inthe shown example, the guide device discloses two attachment brackets19, 20, which are fixed to an attachment surface of the transversalprofile beam 6 in such manner that they between themselves form a gapwhich slightly exceeds the width of the locking slide. At least one ofthe attachment brackets discloses a planar guide surface 21, againstwhich the locking slide is intended to bear with one of its sides, whichalso is planar and forms a guide surface 22. Furthermore, the guidedevice includes a guide pin 23, which extends through the, attachmentbrackets 19, 20 and is kept in place by means of the fact that itsuitably is formed as a bolt. In the shown example, a spring washer 24is clamped between one of the attachment brackets 19 and the lockingslide 14, the purpose of which is to press the locking slide withfreedom from play against the guide surface 21 in the other attachmentbracket. The guide pin 23 namely extends through an arched guide slit 25which determines the guide of the locking slide in its adjustmentmovement between lock position and release position. The guide slit 25has a limited extension and forms in its ends stop bolts for the guidepin in the end positions of the locking slide. The adjustment movementis additionally guided by means of two support lists 26, 27 on theprofile beam 26 by bearing against the surface 17 of the locking slide.Thus, the curved guide surface 17, in cooperation with the position ofthe guide device 15, determines the adjustment movement which follows acurved path, which thus advantageously brings the locking slide towardsthe scaffold element in lock position. In this regard, the curve of thelock surface 16 is suitably selected so that it has a radius which isless than the radius or half the transverse dimension of the scaffoldelement 4 or the radius of curvature of the inside rest surface 10 ofthe hook section 8. The same effect can be obtained by means of the sameradius of curvature and a center of curvature for the locking slide 14which has been shifted inwards.

Thus, the release position for the locking device 1 is shown in FIGS. 1,3, 5 and 7. In this connection, the locking slide is displaced so thatthe guide pin 23 reaches its end position towards the lower end 28, seeFIG. 6, of the guide slit 25. In this manner, the locking slide 14protrudes exceedingly above the platform plane 29, see particularlyFIGS. 1, 3 and 5. This is partly an effect of an eccentrically situatedpath at the locking slide. Alternatively, or in combination with this,the locking slide 14 is, as is shown in the drawings, advantageouslyradially thicker than the hook element 8 in its section above thescaffold element 4. Moreover, seen from above, the locking slideprotrudes in a distinctly manner in relation to the transversal profilebeam 6 as well, see FIG. 7, and interjects over the lying scaffoldelement 4. In this manner, the locking slide forms a visual indicationsection with one of its ends 30 which is clearly visible for an observerfrom the upper side of the platform as well, for example for anindividual which is situated on the platform, which constitutes adistinct indication of the fact that the platform is not entirelyassembled, but that adjustment to lock position is required.Consequently, the first step in the assembly is accomplished by means ofthe fact that the locking slide in release position is removed in suchmanner that the hook opening of the hook element allows the scaffoldelement to be inserted into the hook elements 3. Thus, there is therebya risk that the hook elements are unintentionally unhooked due to unevenload or other disadvantageous conditions, by means of which it isparticularly important that the assembly is completed by means of thelocking device 1 being adjusted to lock position. This is accomplishedby means of the fact that the locking slide, either manually or by meansof a knock by a tool, hammer or the like, is moved towards the endsection or the indication section 30, by means of which the lockingslide in an arched movement is caused to be displaced in relation to theguide device to lock position, which is shown in FIGS. 2, 4, 6 and 8. Inreverse, lock position is in this regard indicated by means of fact thatthe indication section 30 is removed from the projection or protrusionposition, and is in the shown example situated below the platform planeand protrudes insignificantly from the transversal beam 6 seen fromabove. The guide device allows a displacement movement with a suitablyadjusted friction which, apart from the sliding surfaces, is determinedby the spring force in the spring washer 24, the purpose of which is tosecure that lock position is maintained also during forces which striveto unhook the hook elements 3 from the scaffold element 4. A minimumrequirement is that the active hook opening 12, which in the lockposition of the locking slide has been considerably reduced, is smallerthan the transverse dimension of the lying scaffold element 4, i.e. itsdiameter. In practice, the active hook opening should be considerablysmaller than this dimension in order for component forces on the lockingslide not to act to adjust this to release position. At the same time,the locking slide should not be made unnecessarily long in order toavoid bending stresses in this. A suitable opening angle in lockposition is, for example, as in the shown example, approximately 90°.

By means of the locking device according to the invention, an extremelysimple visual or ocular indication is by means of simple means obtainedof whether the locking is adjusted to lock position or not. A signalcolour or a brightly coloured other marking on the locking slide may,for that matter, possibly be arranged on the indication section 30, forexample a plastic pin which is bored through the locking slide.

The invention is not limited to the embodiments which are describedabove and shown in the drawings, but may be varied within the scope ofthe appended claims. For example, the guide device can be constructed ina number of different ways, such as in the form of a guide casing inwhich the locking slide runs. The hooked sections 8 can have a restsurface 10 which has another form that is adapted to anothercross-sectional form of the scaffold element in question, e.g.polygonal, e.g. quadrangular with sharply or rounded-off corners.

What is claimed is:
 1. A locking device for a scaffold platform havingan upper side, comprising: a. a guide device having a guide pin, a firstbracket and a second bracket, the first bracket having a first guidesurface; and b. a locking slide having a release position, a lockposition and a guide slit, the locking slide being disposed between thefirst bracket and the second bracket so that the guide pin is receivedin the guide slit, the locking slide being brought to bear against thefirst guide surface by a spring force so as to guide movement of thelocking slide, the locking slide having an end carrying an indicationthat is visible from the upper side of the scaffold platform when thelocking slide is in the release position.
 2. The device of claim 1,wherein in the locking slides have a curved shape and is moveable in theguide device along a curved path.
 3. The locking device of claim 1,wherein the radial dimension of the locking slide is larger than theradial dimension of the hook element so that the locking slide isvisible and has the indicating section protruding above the hookelement.
 4. The locking device of claim 2, wherein the locking slide hasless play in the lock position than in the release position.
 5. Thelocking device of claim 4, wherein the central of curvature for thelocking slide is eccentric in relation to the center curvature for thescaffold element to be engaged by the locking device.
 6. The lockingdevice of claim 3, wherein the locking slide bears against the scaffoldelement in the locked position.